BACKGROUND: Hepatitis C virus (HCV) infection is frequent in hemophilia patients treated with non-viral inactivated factor concentrates. In Korea, solvent/detergent method was introduced in 1989 and majority of hemophila patients treated before 1989 were infected with HCV. A number of studies have described the identification of virus genotypes in different geographical regions and racial groups. In order to clarify the characteristics of HCV infection in Korean hemophiliacs, we investigated the HCV genotypes in 125 hemophilia patients infected with HCV. METHODS: The HCV infection was confirmed by anti-HCV test and HCV-RNA detection method. To analyze the HCV genotypes, we used the reverse hybridization line probe assay (INNO LiPA HCV II, Innogenetics N.V., Belgium). RESULTS: Among 125 hemophilia patients, ten (8.0%) patients were infected with type 1a, 56 (44.8%) type 1b, 38 (30.4%) ambiguous type 2a/2c, eight (6.4%) type 2b, four (3.2%) type 3a, two (1.6%) type 4. And seven (5.6%) patients had mixed infection (four 1b+2a/2c, one 1a+2a/2c, one 2b+2a/2c, one 1a+2b+2a/2c). CONCLUSION: In Korean hemophiliacs, HCV genotype 1b was the most predominant and 2a/2c the second.